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Beamforming using microphone arrays
Bartoň, Zdeněk ; Schimmel, Jiří (referee) ; Míča, Ivan (advisor)
The aim of the master thesis is to sum up theoretical information about beamforming methods of microphone arrays and to verify their functionality. At the beginning of this work there are simulated different varietes of linear uniform and nonuniform microphone arrays and circular arrays. The results are verificated by a practical measurement in ideal conditions. Then I will focuse on implementation of the DAS(Delay And Sum), SAB(Sub Array Beamforming), CDB(Constant Directivity Beamforming), CDB-CA(CDB-Circular Arrays) beamformer including theoretical and practical verification of the functionality in ideal conditions. At the end of this thesis are all beamforming methods compared with each other at SNR(signal to Noise Ratio) and directivity parameters.
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Methods for detecting acoustic sources using microphone arrays
Durkoš, Michal ; Rampl, Ivan (referee) ; Míča, Ivan (advisor)
his paper denotes various possibilities of localization of sources of acoustic signals. It informs the reader about possibilities of using beamforming and it´s basic conditions and rules. In detail it denotes delay-and-sum beamforming, which can be used for both localization of signal sources and for improving the signal by extending signal-to-noise ratio. In the last part of this paper process of simulation of incidence of sound signal on the microphone array is shown, experimental measures are noted and so is their evaluation.
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Microphone array application
Toman, Vít ; Hanák, Pavel (referee) ; Fedra, Zbyněk (advisor)
Master’s thesis deals with description of issues of reading spatial audio signals using microphone array. Basic method of beamforming (Delay and Sum) is characterized on basis of chosen conception of the microphone array. Specific issues of audio detection and digital signal processing of converted audio signals are characterized and some ways how to solve the issues are adumbrated. Features and limitations of chosen ARM processor in the digital processing of multiple audio signals are described. Especially features and limitations of an internal A/D converter from the perspective of the beamforming are described.
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Microphone arrays for beamforming
Grénar, Milan ; Smékal, Zdeněk (referee) ; Míča, Ivan (advisor)
The aim of the bachelor's thesis is to assemble theoretical and practical information about methods for estimate direction of arrival whereas there is an emphasis on beamforming. There are introduced general conventions which are being used to measure with multichannel microphone array. Part of this thesis is the implementation of the DAS beamformer in several modifications, including verification of the functionality in ideal and real conditions.
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Acoustic Detection of Speaker Position Using Microphone Array
Pelz, Zdeněk ; Novotný, Ondřej (referee) ; Szőke, Igor (advisor)
This thesis explores problematics of speaker localization using microphone array. Aim of this thesis is implementation of algorithms for speaker localization and experiments with those algorithms. Calculation of TDOA was done using cross-correlation and hyperbolic method was used to calculate position estimation. Finished microphone array is able to locate speaker within certain variance. Results of this thesis allow reader to make assumptions regarding accuracy of localisation using microphone array and ARM kit with limited performance. Precision of position estimation using microphone array reached several decimeters, but this precision is dependent on distance from microphone array.
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Acoustic detection of starlings through artificial intelligence
Zezula, Benjamin ; Vlachová Hutová, Eliška (referee) ; Marcoň, Petr (advisor)
To protect the vineyards from starlings is very costly and ineffective with the available resources over a period of time. In my project, I have designed a detection module that relays information about the flock location in the vineyard to the control module and thus produces scaring. I have designed two kinds of detection modules, which are compared. The first variant consists of a single directional microphone that rotates and sequentially senses the entire area of the vineyard. The second variant consists of four microphones, each one is directed to the cardinal point and based on the intensity of sound, the module will provide the information about the direction where the flock is located. Both detection modules process the signal in a Raspberry Pi 4 single board computer using an artificial neural network algorithm powered by MobileNetV2 architecture.
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Lossless Coding of Speech from Microphone Array
Myška, David ; Černocký, Jan (referee) ; Malenovský, Vladimír (advisor)
This bachelor's thesis deals with lossless coding of speech signals from microphone arrays. It describes the methods used in the FLAC reference codec and their variations to increase compression for signals from microphone arrays. The following describes methods for aligning channels for their subsequent processing. At the end of the work the results obtained are compared with the reference codec FLAC.
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Acoustic Holography
Vacula, Jan ; Janoušek, Michal (referee) ; Prokop, Aleš (advisor)
This bachelor´s thesis is focused on description and process during contactless identification of sound source for near and far field. Principles of individual methods of acoustic holography are relatively shortly described and for details of this problem (on the level of algorithm of software equipment) you can see the references below thesis, which were the basic theory of my study. The introduction was conceived like description of “acoustics world”. You can find the basic information and principles about sound propagation in space and their mathematical contain at time. For this it was essential to define quantity and their units. Subsequently there is inventory of used sensors and their own construction for this measurement. Next chapter point to some techniques of acoustic holography used in practice. It includes mainly a method NAH (Nearfield Acoustical Holography) and SONAH (Statistically Optimised Nearfield Acoustical Holography) used for near-field. For reconstruction of far-field is shown principle of a method of Beamforming and manual measurement by intensity probe. The ending is focused on a concrete application these methods on combustion engines of cars.
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Statical acoustical sources localization
Mikeš, Petr ; Holešinský, Pavel (referee) ; Míča, Ivan (advisor)
The microphone array can be used in many important applications. The primary usage, which most of other applications are based on, is only: acoustic sources localization and separation of each signal from their compound. The microphone array is usually included in ordinary mobile phones, where it reduces noise and sound of its surrounding that otherwise degrades vocal speech. Other microphone array utilization is in for example speech identification, speakers’ localization or signal isolation of one speaker.
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